Sharing of Investigational Drug Among Participants in the Voice Trial

Product sharing among participants can impact on adherence and compromise the outcome in clinical trials. We describe incidents of product sharing at the Durban clinical research sites conducting the VOICE trial. The Durban sites enrolled 2750 women with 1103 and 1647 participants randomized to the vaginal gel and oral tablet arms respectively. Monthly pill and applicator counts including product assessments were conducted by pharmacists. Discrepancies with product counts prompted discussions with participants. Thirty-two cases of product sharing were identified. Vaginal gels were more commonly shared than oral tablets. Product sharing between study participants and their female friends or relatives living in the same household was identified as the most common source of product sharing in this analysis. Study product counts and pharmacist-driven discussions with participants may help to identify reasons for product sharing and inform the development of strategies for PrEP implementation outside of the research setting.